Mercurial > cgi-bin > hgwebdir.cgi > VMS > C_Libraries > Queue_impl

comparison BlockingQueue.c @ 7:08f0b4da7610

find changesets by author, revision, files, or words in the commit message
Works with pin2core.. not sure changes made..
author Me
date Wed, 01 Sep 2010 09:16:24 -0700
parents 174a7c2ca340
children 62326cc8e6f4 53c614b781ce
comparison
equal deleted inserted replaced
3:084cb48da029 4:0686b20358ef
134 { void *out = 0; 134 { void *out = 0;
135 int tries = 0; 135 int tries = 0;
136 void **startOfData = Q->startOfData; 136 void **startOfData = Q->startOfData;
137 void **endOfData = Q->endOfData; 137 void **endOfData = Q->endOfData;
138 138
139 int success = FALSE; 139 int gotLock = FALSE;
140 140
141 while( TRUE ) 141 while( TRUE )
142 { success = 142 { //this intrinsic returns true if the lock held "UNLOCKED", in which
143 // case it now holds "LOCKED" -- if it already held "LOCKED", then
144 // gotLock is FALSE
145 gotLock =
143 __sync_bool_compare_and_swap( &(Q->extractLock), UNLOCKED, LOCKED ); 146 __sync_bool_compare_and_swap( &(Q->extractLock), UNLOCKED, LOCKED );
144 //NOTE: checked assy, and it does lock correctly.. 147 //NOTE: checked assy, and it does lock correctly..
145 if( success ) 148 if( gotLock )
146 { 149 {
147 void **insertPos = Q->insertPos; 150 void **insertPos = Q->insertPos;
148 void **extractPos = Q->extractPos; 151 void **extractPos = Q->extractPos;
149 152
150 //if not empty -- extract just below insert when empty 153 //if not empty -- extract just below insert when empty
160 out = *(Q->extractPos); 163 out = *(Q->extractPos);
161 Q->extractLock = UNLOCKED; 164 Q->extractLock = UNLOCKED;
162 return out; 165 return out;
163 } 166 }
164 else //Q is empty 167 else //Q is empty
165 { success = FALSE; 168 { Q->extractLock = UNLOCKED;//empty, so release lock for others
166 Q->extractLock = UNLOCKED;//have to try again, release for others
167 } 169 }
168 } 170 }
169 //Q is busy or empty 171 //Q is busy or empty
170 tries++; 172 tries++;
171 if( tries > SPINLOCK_TRIES ) pthread_yield(); //not reliable 173 if( tries > SPINLOCK_TRIES ) pthread_yield(); //not reliable
178 //TODO: need to make Q volatile? Want to do this Q in assembly! 180 //TODO: need to make Q volatile? Want to do this Q in assembly!
179 //Have no idea what GCC's going to do to this code 181 //Have no idea what GCC's going to do to this code
180 void **startOfData = Q->startOfData; 182 void **startOfData = Q->startOfData;
181 void **endOfData = Q->endOfData; 183 void **endOfData = Q->endOfData;
182 184
183 int success = FALSE; 185 int gotLock = FALSE;
184 186
185 while( TRUE ) 187 while( TRUE )
186 { success = 188 { //this intrinsic returns true if the lock held "UNLOCKED", in which
189 // case it now holds "LOCKED" -- if it already held "LOCKED", then
190 // gotLock is FALSE
191 gotLock =
187 __sync_bool_compare_and_swap( &(Q->insertLock), UNLOCKED, LOCKED ); 192 __sync_bool_compare_and_swap( &(Q->insertLock), UNLOCKED, LOCKED );
188 if( success ) 193 if( gotLock )
189 { 194 {
190 void **insertPos = Q->insertPos; 195 void **insertPos = Q->insertPos;
191 void **extractPos = Q->extractPos; 196 void **extractPos = Q->extractPos;
192 197
193 //check if room to insert.. can't use a count variable 198 //check if room to insert.. can't use a count variable
203 } 208 }
204 Q->insertLock = UNLOCKED; 209 Q->insertLock = UNLOCKED;
205 return; 210 return;
206 } 211 }
207 else //Q is full 212 else //Q is full
208 { success = FALSE; 213 { Q->insertLock = UNLOCKED;//full, so release lock for others
209 Q->insertLock = UNLOCKED;//have to try again, release for others
210 } 214 }
211 } 215 }
212 tries++; 216 tries++;
213 if( tries > SPINLOCK_TRIES ) pthread_yield(); //not reliable 217 if( tries > SPINLOCK_TRIES ) pthread_yield(); //not reliable
214 } 218 }
245 retQ->endOfData = &(retQ->startOfData[1023]); 249 retQ->endOfData = &(retQ->startOfData[1023]);
246 250
247 return retQ; 251 return retQ;
248 } 252 }
249 253
254 void
255 freeSRSWQ( SRSWQueueStruc* Q )
256 {
257 free( Q );
258 }
250 259
251 void* readSRSWQ( SRSWQueueStruc* Q ) 260 void* readSRSWQ( SRSWQueueStruc* Q )
252 { void *out = 0; 261 { void *out = 0;
253 int tries = 0; 262 int tries = 0;
254 263
281 out = *(Q->extractPos); 290 out = *(Q->extractPos);
282 return out; 291 return out;
283 } 292 }
284 //Q is empty 293 //Q is empty
285 tries++; 294 tries++;
286 if( tries > 2 ) return 0; //long enough for writer to finish 295 if( tries > 10 ) return NULL; //long enough for writer to finish
287 } 296 }
288 } 297 }
289 298
290 299
291 void writeSRSWQ( void * in, SRSWQueueStruc* Q ) 300 void writeSRSWQ( void * in, SRSWQueueStruc* Q )